Technical Abstract:
Various chemical and biological measures were determined in carp (Cyprinus carpio) sampled from seven sites along a 74-mile length of the Cuyahoga River, Ohio. At the uppermost site (site 1) the headwaters have been shown to be relatively pristine, with the lower portion heavily polluted from various industrial, urban and wastewater treatment plants (WWTP). Levels of nonylphenol ethoxylates (NP (nonylphenol), NP1EO, NP2EO and total NPEs) in fish increased in a downstream direction, with maximal values observed near the discharge of the Akron WWTP (Site 6). As this class of compounds have been demonstrated to exert estrogenic effects on fish species, various biological parameters were measured. Larger fish were observed (length, weight and gonad weight) in upstream locations and so statistical analyses were carried out using 1-way ANOVAs (sex separate) using log weight as the covariate. We observed no differences between site in condition factor, lipid content or GSI of either sexes. In female fish a trend to lower levels of VTG at the downstream sites was observed but there were no significant differences between sites in levels of vitellogenin (VTG), or in levels of 17b-estradiol (E). However, differences were observed between sites using the measures of 11-ketotestosterone (11-KT) and the ratio E/11-KT. In laboratory studies using carp it has been shown that NPEs will induce VTG formation in males. The highest levels of VTG were observed at Site 6, paralleling the high levels of NPEs, however, this was not significant and no significant differences in levels of VTG were observed between sites. In addition no site differences were observed in the measures of E, 11-KT and the E/11-KT ratio. Comparisons of these findings will be made to similar data collected from carp that were obtained from waterways in the Chicago area.